pub mod arr_enum {
    pub mod vowel {

        // 定义一个包含所有 Vowel 枚举变体的数组
        pub const ALL_VOWELS: [&str; 5] = ["A", "E", "I", "O", "U"];
    }
    pub mod staff {
        #[derive(Debug)]
        pub enum StaffEnum {
            Engineering,
            Sales,
            HR,
        }
        impl StaffEnum {
            pub fn to_string(&self) -> String {
                let str = match self {
                    StaffEnum::Engineering => String::from("Engineering"),
                    StaffEnum::Sales => String::from("Sales"),
                    StaffEnum::HR => String::from("HR"),
                    _ => String::from("other"),
                };
                str
            }
        }
    }
}
